JP7446005B1 - Golf ball - Google Patents

Abstract

A dimple (12) formed on a golf ball (10) includes a bottom surface (14), an opening periphery (16), and an inner wall portion (18) that tapers from the opening periphery toward the bottom surface. and has. The bottom has a diametrically inner portion, a first bottom portion (20), and a diametrically outer portion, a second bottom portion (22). The intersection angle θ1 between the first imaginary horizontal line (M1) passing through the opening periphery and the inner wall is 3° to 62°. The shortest distance d2 between the shallowest part (DS) of the second bottom part and the first virtual horizontal line is 30% of the shortest distance d1 between the deepest part (DM) of the first bottom part and the first virtual horizontal line. ~70%. [Selection diagram] Figure 2

Description

The present invention relates to a golf ball having dimples on its surface.

A plurality of dimples are formed on the surface of a golf ball in order to stabilize the flight trajectory and increase the flight distance when the ball is hit. A typical dimple has a shape similar to a small hole cut out from the surface of a golf ball, but recently, various studies have been conducted on the shape of the dimple in order to further increase flight distance.

For example, Patent Document 1 proposes a dimple shape in which a curved part formed on the center side and an inclined straight part formed on the peripheral side appear in a cross section along the depth direction. . Here, the straight line portion includes a first straight line portion continuous to the curved portion and a second straight line portion continuous to the end portion of the first straight line portion on the peripheral edge side. The slope relative to the surface of the golf ball in the second straight portion is greater than the slope relative to the surface of the golf ball in the first straight portion.

Japanese Patent Application Publication No. 2003-79763

In a shot using a driver club (driver shot), if the amount of spin of the golf ball is excessively high, the trajectory will be so-called blown up. In this case, the flight distance of the golf ball may decrease. On the contrary, in a shot using a short iron or a wedge club (approach shot), if the amount of spin of the golf ball is too small, it is difficult to stop the golf ball at or near the target point.

Therefore, there is a need for a golf ball that can provide a sufficient flight distance on driver shots and that can be easily stopped at or near the point intended by the player on approach shots.

The present invention aims to solve the above-mentioned problems.

According to an embodiment of the present invention, in a golf ball having dimples on the surface, the dimples are formed by a bottom surface having a first diameter and a peripheral edge of a circular opening, and the dimples have a first diameter larger than the first diameter. an opening periphery having a diameter of 2; and an inner wall portion extending from the opening periphery toward the bottom surface and tapered when viewed along the depth direction of the dimple; a first bottom part that forms a diametrically inner part of the bottom face and is curved in an arc shape when viewed along the depth direction of the dimple; forming a diametrically outer portion of the dimple and extending linearly when viewed along the depth direction of the dimple, the first diameter being equal to the second diameter. a second imaginary horizontal line having a length of 80% to 95%, passing through the intersection of the first imaginary horizontal line passing through the opening periphery, and the first bottom part and the second bottom part and parallel to the first imaginary horizontal line; θ1 is 3° to 62° and θ1>θ2, the shortest distance between the deepest part of the first bottom part and the first virtual horizontal line is d1, and the distance between the shallowest part of the second bottom part and the When the shortest distance from the first virtual horizontal line is d2, a golf ball is provided in which d2 is 30% to 70% of the length of d1.

A golf ball in which the dimensions of the dimples are set as described above provides a sufficient flight distance on driver shots. Further, this golf ball rotates with a sufficient amount of spin on approach shots. Therefore, it is easy to stop the golf ball at or near the target point on an approach shot.

FIG. 1 is a schematic overall plan view of a golf ball according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view along the depth direction of the dimple. FIG. 3 is a schematic cross-sectional view along the depth direction of a dimple having a peripheral wall portion. FIG. 4 is a chart showing various dimensions of dimples in the golf ball of Reference Example 1. FIG. 5 is a chart showing various dimensions of dimples in the golf ball of Example 2. FIGS. 6A and 6B are charts showing results obtained by ball hitting tests for golf balls of Reference Example 1, Example 2, and Comparative Example.

In the following explanation, flight distance refers to the total value of the distance from the shot point to the landing point (carry) and the distance from the landing point to the stopping point (run) when hitting a golf ball.

FIG. 1 is a schematic overall plan view of a golf ball 10 according to the present embodiment. Golf ball 10 includes a plurality of dimples 12 on its surface. The dimple 12 is a concave portion depressed from the surface of the golf ball 10, and has a circular opening on the surface of the golf ball 10. One dimple 12 has a bottom surface 14 , an opening periphery 16 formed by the periphery of the opening, and an inner wall 18 . When a player views the golf ball 10 in plan, the dimples 12 are visible from above in the depth direction. At this time, the bottom surface 14 and the opening periphery 16 are circular.

FIG. 2 is a schematic cross-sectional view of the dimple 12 taken along the depth direction. As understood from FIG. 2, the bottom surface 14 of the dimple 12 has a bottom diameter ΦB as a first diameter. The opening periphery 16 of the dimple 12 has an opening diameter ΦA as the second diameter. The bottom diameter ΦB is smaller than the opening diameter ΦA. However, if the bottom diameter ΦB is too small with respect to the opening diameter ΦA, the trajectory tends to be upward when shot with a driver, resulting in a reduction in flight distance. Further, the amount of spin of the golf ball 10 may be insufficient on approach shots. In order to avoid this, the bottom diameter ΦB is set to a length of 80% to 95% of the opening diameter ΦA.

The opening diameter ΦA is preferably within the range of 3.0 mm to 5.5 mm. When the opening diameter ΦA is 5.0 mm, the bottom diameter ΦB is, for example, 4.6 mm.

It is not particularly necessary that the bottom diameter ΦB and the opening diameter ΦA of all the dimples 12 be the same. In this embodiment, the dimple 12 includes first dimples 12a to fifth dimples 12e having different opening diameters ΦA, as shown in FIG. However, the first dimple 12a to the fifth dimple 12e all have the shape shown in FIG.

The opening diameter ΦA becomes smaller in the order of the first dimple 12a, the second dimple 12b, the third dimple 12c, the fourth dimple 12d, and the fifth dimple 12e. Examples of opening diameters ΦA of the first dimple 12a to the fifth dimple 12e are 5.0 mm, 4.8 mm, 4.5 mm, 4.2 mm, and 3.5 mm, respectively. In this case, the ratio of each bottom diameter ΦB to each opening diameter ΦA of the first dimple 12a to fifth dimple 12e is, for example, 92.0%, 91.7%, 91.1%, 90.5%, and 88%. .6%. Examples of the numbers of the first dimples 12a, second dimples 12b, third dimples 12c, fourth dimples 12d, and fifth dimples 12e are 80, 40, 130, 10, and 12, respectively. .

The opening diameter ΦA and the number of each of the first dimples 12a to fifth dimples 12e are not particularly limited to the above values. Furthermore, the number of dimples 12 having a different opening diameter ΦA from the first dimple 12a to the fifth dimple 12e may be further increased. Alternatively, one or more of the first dimples 12a to the fifth dimples 12e may be omitted.

As shown in FIG. 2, the bottom surface 14 of the dimple 12 has a first bottom surface portion 20 and a second bottom surface portion 22. As shown in FIG. The first bottom portion 20 forms a diametrically inner portion of the bottom surface 14 . The first bottom surface portion 20 is curved in an arc shape when viewed along the depth direction of the dimple 12. The first bottom portion 20 has a radius of curvature R. The radius of curvature R is set to be smaller in the order of, for example, the first dimple 12a to the fifth dimple 12e. In the first bottom portion 20, the most depressed portion is the deepest portion DM.

The opening diameter ΦA of the dimple 12 is preferably within the range of 18% to 50% of the radius of curvature R, and more preferably within the range of 25% to 45% of the radius of curvature R. In a typical example, the radius of curvature R of the first dimple 12a to the fifth dimple 12e is 17.4 mm, 16.0 mm, 14.1 mm, 12.2 mm, and 8.6 mm, respectively. When the opening diameter ΦA of the first dimple 12a to the fifth dimple 12e is the above-mentioned value, the opening diameter ΦA of the first dimple 12a is 28.7% of the radius of curvature R. Further, the opening diameters ΦA of the second dimple 12b to the fifth dimple 12e are 29.9%, 32.0%, 34.4%, and 40.6% of the radius of curvature R, respectively.

The second bottom portion 22 forms a diametrically outer portion of the bottom surface 14 . That is, the second bottom part 22 surrounds the first bottom part 20. The second bottom surface portion 22 extends linearly when viewed along the depth direction of the dimple 12 . The bottom diameter ΦB is the diameter of a circle passing through the shallowest portion DS in the second bottom surface portion 22.

The first bottom part 20 and the second bottom part 22 intersect at an intersection A. Here, a virtual horizontal line passing through the intersection A and drawn parallel to the first virtual horizontal line M1 is defined as a second virtual horizontal line M2. Note that the first virtual horizontal line M1 is a virtual horizontal line that passes through the opening periphery 16.

The shortest distance between the deepest part DM of the first bottom surface part 20 and the first virtual horizontal line M1 is defined as a first distance d1. In this embodiment, the first distance d1 is preferably within a range of 0.10 mm to 0.20 mm. In a typical example, the first distance d1 between the first dimple 12a to the fourth dimple 12d is 0.130 mm, and the first distance d1 between the fifth dimple 12e is 0.125 mm.

Further, the shortest distance between the shallowest portion DS in the second bottom surface portion 22 and the first virtual horizontal line M1 is defined as a second distance d2. If the second distance d2 is too small, it will not be easy to prevent the golf ball 10 from flying up on a driver shot. Further, the amount of spin may be insufficient on approach shots. For these reasons, it is preferable to set the second distance d2 within a range of 30% to 70% of the first distance d1. In a typical example, the second distance d2 is set to 0.085 mm in the first dimple 12a to the fifth dimple 12e. As described above, when the first distance d1 between the first dimple 12a and the fourth dimple 12d is 0.130 mm, and the first distance d1 between the fifth dimple 12e and the fifth dimple 12e is 0.125 mm, the distance between the first dimple 12a and the fourth dimple 12d is 12d, the second distance d2 is 65.4% of the first distance d1. In the fifth dimple 12e, the second distance d2 is 68.0% of the first distance d1.

The inner wall portion 18 is an inner peripheral wall of the dimple 12 and extends from the opening periphery 16 toward the shallowest portion DS of the second bottom surface portion 22. The inner wall portion 18 tapers from the opening periphery 16 toward the shallowest portion DS of the second bottom surface portion 22 . In other words, when the dimple 12 is viewed along the depth direction, the inner wall portion 18 is inclined in a tapered shape.

The intersection angle between the inner wall portion 18 and the first virtual horizontal line M1 is defined as a first angle θ1. If the first angle θ1 is too small, the amount of spin of the golf ball 10 may not be sufficient on approach shots. If the first angle θ1 is too large, the flight trajectory of the golf ball 10 will be low, and as a result, the flight distance may be insufficient. In order to avoid this, the first angle θ1 is preferably within the range of 3° to 62°. A more preferable range of the first angle θ1 is 15° to 25°.

The intersection angle between the second bottom surface portion 22 and the second virtual horizontal line M2 is defined as a second angle θ2. The relationship θ1>θ2 holds between the first angle θ1 and the second angle θ2. If the second angle θ2 is too large, it is not easy to improve flight distance. Further, the amount of spin of the golf ball 10 may be insufficient on approach shots. To avoid this, the second angle θ2 is preferably within the range of 0.2° to 6.0°. A more preferable range of the second angle θ2 is 0.5° to 2.0°.

The opening diameter ΦA of the dimple 12, the bottom diameter ΦB, ΦB/ΦA, the first distance d1, the second distance d2, d2/d1, the radius of curvature R of the first bottom portion 20, the first angle θ1, and the second angle θ2 are greater than or equal to According to the golf ball 10 having the dimples 12 (first dimple 12a to fifth dimple 12e) set as shown above, a sufficient flight distance can be obtained on driver shots. Further, this golf ball 10 rotates with a sufficient amount of spin during an approach shot. Therefore, it is easy to stop the golf ball 10 at or near the target point.

As shown in FIG. 3, a peripheral wall portion 30 may be interposed between the second bottom surface portion 22 and the inner wall portion 18. The peripheral wall portion 30 in FIG. 3 is bent to intersect the second bottom surface portion 22 and the inner wall portion 18 at a predetermined angle. However, the peripheral wall portion 30 is not particularly limited to this shape. For example, the peripheral wall portion 30 may be a curved portion with an extremely small radius of curvature. In either case, the peripheral wall portion 30 is bent and continuous with the second bottom surface portion 22 and the inner wall portion 18.

Opening diameter ΦA, bottom diameter ΦB, ΦB/ΦA, the shortest distance (first distance) d1 between the first bottom part 20 and the first virtual horizontal line M1, the shallowest part DS of the second bottom part 22 and the first virtual The shortest distance (second distance) d2, d2/d1 from the horizontal line M1, the radius of curvature R, ΦA/R of the first bottom part 20, the intersection angle between the inner wall part 18 and the first virtual horizontal line M1 (the first angle) θ1, and the intersection angle (second angle) θ2 between the second bottom surface portion 22 and the second virtual horizontal line M2, the golf ball 10 having the first dimple 12a to the fifth dimple 12e shown in FIGS. 4 and 5. Each was produced. The respective golf balls 10 are referred to as Reference Example 1 and Example 2.

Since this is a comparative example, the opening diameter ΦA and the first distance d1 are the same as those of Reference Example 1 and Example 2, and the bottom surface in which only one curved surface appears in the cross section along the depth direction, and the opening periphery connected to the bottom surface. A golf ball having five types of dimples consisting of an inner wall portion extending to

A first tester hits the golf balls 10 of Reference Example 1 and Example 2 and the golf ball of Comparative Example with a driver, and determines the maximum height of each ball and the distance from the shot point to the landing point ( Carry) and flight distance from the shot point to the stopping point (total value of carry and run) were measured. The results of this driver shot are shown in FIG. 6A.

Further, the number of spins of each golf ball 10 was determined when the first tester hit the golf balls 10 of Reference Example 1 and Example 2 and the golf ball of Comparative Example with a wedge club. The results of this approach shot are also shown in FIG. 6A.

A second tester hit the golf balls 10 of Reference Example 1 and Example 2 and the golf ball of Comparative Example in the same manner as described above. The results for driver shots and approach shots are shown in FIG. 6B.

It can be seen from FIGS. 6A and 6B that the driver shot with the golf ball of the comparative example has a higher trajectory than each of the golf balls 10 of Reference Example 1 and Example 2. Therefore, in a driver shot with the golf ball of the comparative example, the flight distance is smaller than that of each of the golf balls 10 of the first reference example and the second example . In other words, by forming the dimples 12 as in Reference Example 1 and Example 2, the flight distance of the golf ball 10 can be increased.

Furthermore, from FIGS. 6A and 6B, it can be seen that the golf balls 10 of Reference Example 1 and Example 2 achieve a greater amount of spin than the golf ball of Comparative Example on approach shots. This indicates that each of the golf balls 10 of Reference Example 1 and Example 2 is easier to stop at or near the target point than the golf ball of Comparative Example.

Next, the golf balls 10 of Reference Example 1 and Example 2 and the golf ball of Comparative Example were subjected to ITR (Indoor Test Range) measurement for measuring aerodynamic characteristics during flight. As a result, in each of the golf balls 10 of Reference Example 1 and Example 2, excessive lift is suppressed in the flight region where the amount of spin is high immediately after hitting the ball, and the ball flies with low drag until reaching near the highest point, and It was confirmed that the lift force was sustained from near the arrival point until landing. As a result, the flight distance of each golf ball 10 of Reference Example 1 and Example 2 becomes greater than the flight distance of the golf ball of Comparative Example.

Further, by structural analysis using the finite element method, the stress distribution around the dimples 12 was analyzed when a load was applied to a golf ball placed on a 3D model imitating a golf club face. For this structural analysis, numerical values of the material properties of the golf ball were used. As a result, each of the golf balls 10 of Reference Example 1 and Example 2 deforms while applying a larger stress to the periphery of the dimple 12 than the golf ball of the comparative example, and the dimple 12 exerts a larger force on the golf club face. The analysis results showed that the two were in contact with each other.

As described above, in the present embodiment, in a golf ball (10) having dimples (12) on the surface, the dimples have a bottom surface (14) having a first diameter (ΦB) and a peripheral edge of a circular opening. an opening periphery (16) formed by a second diameter (ΦA) that is larger than the first diameter; an inner wall portion (18) tapering in a tapered manner, the bottom surface forming a diametrically inner portion of the bottom surface and curved in an arc shape when viewed along the depth direction of the dimple. a first bottom surface portion (20) located diametrically outwardly of the first bottom surface portion to form a diametrically outer portion of the bottom surface, and having a linear shape when viewed along the depth direction of the dimple; a second bottom surface portion (22) extending in the opening, the first diameter is 80% to 95% of the second diameter, and the first imaginary horizontal line (M1 ) and a second imaginary horizontal line (M2) passing through the intersection (A) of the first bottom surface part and the second bottom surface part and parallel to the first imaginary horizontal line, When the intersection angle with the virtual horizontal line is θ1, and the intersection angle between the second bottom part and the second virtual horizontal line is θ2, θ1 is within the range of 3° to 62°, and θ1>θ2. , the shortest distance between the deepest part (DM) of the first bottom part and the first virtual horizontal line is d1, and between the shallowest part (DS) of the second bottom part and the first virtual horizontal line. Discloses a golf ball in which d2 is 30% to 70% of the length of d1, where the shortest distance is d2.

A golf ball in which the various dimensions of the dimples are set as described above can provide a sufficient flight distance on driver shots. Further, this golf ball rotates with a sufficient amount of spin on approach shots. Therefore, it is easy to stop the golf ball at or near the target point on an approach shot.

In this embodiment, the second diameter is 18% to 50% of the radius of curvature (R) of the first bottom portion and is within the range of 3.0 mm to 5.5 mm, and the shortest distance d1 is 0. A golf ball is disclosed that is within the range of 10 mm to 0.20 mm.

The present embodiment discloses a golf ball in which the crossing angle θ2 is within a range of 0.2° to 6.0°.

In either case, the trajectory of the golf ball being blown up can be further avoided, especially in driver shots. Further, the amount of spin on approach shots becomes even more sufficient. That is, a golf ball can be obtained that allows a more sufficient flight distance to be obtained on driver shots and that makes it easier to stop the golf ball at or near the target point on approach shots.

The present embodiment discloses a golf ball in which a peripheral wall portion (30) that is bent and continuous with the inner wall portion and the second bottom portion is interposed between the inner wall portion and the second bottom portion. .

With this configuration, as in the above, a golf ball can be obtained that provides a sufficient flight distance on driver shots and that makes it easy to stop the golf ball at or near the target point on approach shots.

Note that the present invention is not limited to the disclosure described above, and can take various configurations without departing from the gist of the present invention.

10... Golf ball 12, 12a to 12e... Dimple 14... Bottom surface 16... Opening periphery 18... Inner wall portion 20... First bottom surface portion 22... Second bottom surface portion 30... Peripheral wall portion DM... Deepest part of first bottom surface portion DS... Shallowest part of the second bottom part M1...first virtual horizontal line M2...second virtual horizontal line

Claims (4)

In a golf ball with dimples on the surface,
The dimple has a bottom surface having a first diameter;
an opening peripheral edge formed by a peripheral edge of a circular opening and having a second diameter larger than the first diameter;
an inner wall portion extending from the opening periphery toward the bottom surface and tapered when viewed along the depth direction of the dimple;
has
The bottom surface includes a first bottom surface that forms a diametrically inner portion of the bottom surface and is curved in an arc shape when viewed along the depth direction of the dimple, and a first bottom surface that is located diametrically outward of the first bottom surface. a second bottom surface portion forming a diametrically outer portion of the bottom surface and extending linearly when viewed along the depth direction of the dimple;
The first diameter has a length of 80% to 95% of the second diameter,
A first imaginary horizontal line passing through the periphery of the opening and a second imaginary horizontal line passing through the intersection of the first bottom part and the second bottom part and parallel to the first imaginary horizontal line are drawn, When the intersection angle with the first virtual horizontal line is θ1, and the intersection angle between the second bottom part and the second virtual horizontal line is θ2, θ1 is within the range of 3° to 62°, and θ1>θ2 and
The shortest distance between the deepest part of the first bottom part and the first virtual horizontal line was d1, and the shortest distance between the shallowest part of the second bottom part and the first virtual horizontal line was d2. When, d2 is 30% to 48 % of the length of d1, a golf ball. The golf ball according to claim 1, wherein the second diameter is 18% to 50% of the radius of curvature of the first bottom portion and is within the range of 3.0 mm to 5.5 mm.
A golf ball, wherein the shortest distance d1 is within a range of 0.10 mm to 0.20 mm. The golf ball according to claim 1 or 2, wherein the intersection angle θ2 is within a range of 0.2° to 6.0°. 3. The golf ball according to claim 1, wherein a peripheral wall part that is bent and continuous with the inner wall part and the second bottom part is interposed between the inner wall part and the second bottom part. .